A friend of mine is writing a musical about
Æthelflæd, Queen of Mercia, and has asked me to make a font for the libretto. He's asking for something with a mediaeval feel to it but easily readable. I've gone for a kind of textura, since most of what we know about Æthelflæd comes from later chroniclers, and because it's a lot more readable than proper insular.
I'm really in the early stages, and what you see below is all the glyphs I've got, but it's good to check in early. How is it going?

I'm really struggling with the /d - trying to find a compromise which makes the textura construction more familiar for modern readers.
Comments
Pay attention to counter sizes: I think /h's and o's are too wide.
http://www.themicrofoundry.com/ss_fraktur1.html
A libretto does not need to be typographically allusive; it needs to be highly legible. The audience will never see it. If you want to make a blackletter face, use it for the publicity materials, but don't make the actors contend with it. It's hard enough reading dialogue, lyrics, and music — while learning blocking and choreography — from a script that you're holding in one hand while you're rehearsing.
Besides which, the typography of musical theatre librettos follows a standard format that requires all sorts of typographic distinctions. Full caps, small caps, bold, and italic are all used for specific purposes. Song names are often typeset white-on-black, with the black bands bleeding off the edge for easy location when flipping through. Will your font have all these variations? Have you tested it reversed out of black?
And then there are the practical workflow concerns. Typically, the book writer, lyricist, and composer (not to mention the director, stage manager, dramaturg, etc.) will all want access to the live, editable files to make changes, especially if this is the first production of a new musical. They won't have, and won't want to install, a new font.
Theatrical rehearsal or production scripts are often set in Palatino, which works well, and which most people have already. When no one else needs to collaborate on a script, I've sometimes used Scala, which also works well. Note that the standard format for production scripts is very different from the format of published scripts! Text should be large, at least 12 pt. Scripts should always be printed single-sided and bound with brass fasteners or put in three-ring binders. There are often special concerns for page numbers, as well.
Use your blackletter face on posters, etc, or maybe on the title page of the libretto. But not for the text. Your actors will appreciate you greatly if you give them a simple, clear, legible script that conforms to industry norms.
The real answer to your question, Hrant, is yes and no. Directors put a great deal of thought into establishing the atmosphere of the rehearsal room. For this reason, I have sometimes considered doing some very subtle typographic styling for rehearsal scripts. But in the end utilitarian concerns outweigh everything else. Ultimately, scripts are internal documents. They are never seen by the public. They need to be efficient tools for the actors' use, and they need to function in a way that allows multiple people to collaborate on the files.
But if you're looking to improve the typography of something theatre-related, have a go at playbills! They are often terribly designed, including on Broadway. West End playbills are better, but you have to pay for them. Beware, though: everyone's contract has specific requirements about the typography for their program credit, and these can often be very stringent and legally must be honored to the letter (so to speak).
For anyone who may not be familiar with how musical theatre scripts look, I've attached a couple of pages of one here.
This is set in Adobe Garamond, but Palatino is more common in my experience. Note the use of all caps for lyrics. Because lyrics may be intermingled with dialogue, caps vs u&lc is often the only indication of whether a line is spoken or sung. Scene titles/numbers are in, apparently, Helvetica bold. Orchestral cues are white on black. Note that orchestral cue "#7a," in the black band on the second page, isn't a "song"; it's a little bit of incidental music to cover the transition from one location to another.
BTW, I said "Ae", not "AE"...
I put a set of those in one of my typefaces, coded as Discretionary Ligatures, although strictly speaking as there is only one character, it’s not a ligature.
Can’t recall why, probably just for the hell of it!
I called her Queen of the Mercians, not him. I'm not a history buff. I accept it may not be technically true, but she is much revered here in Gloucester where I live.
I would assume that the printed libretto would be intended more as a souvenir of the performance than of something the audience would make use of during the performance.
(A couple of non-typographical notes: Ordinarily, at least in commercial U.S. theatre, musical theatre scripts are guarded zealously and would never be distributed to the audience, even as paid souvenirs. This is a marked difference between the intellectual property practices of straight and musical theatre. Scripts for straight plays can often be bought through normal trade channels, and they are also often available for purchase as souvenirs at major productions. Musical theatre scripts, on the other hand, are made deliberately inaccessible, and it is virtually impossible to get ahold of them unless you are involved in a licensed production. When I have needed to cite a musical in my research, I have had to rent a hard copy, which arrives in the mail accompanied by all sorts of dire warnings, and which I then mail back to the licensing agency within a set time. Obviously, commemorative editions of blockbuster hits like the coffee-table Hamilton libretto are an exception.
Regarding genre: the contemporary distinction between opera and musical theatre has little to do with whether there is spoken dialogue, recitative, etc. It has more to do with the stylistic tradition of the piece, its production approach and position within the cultural landscape, and its intended audience. Les Misérables, Once on This Island, and Hamilton, for instance, are all "sung-through" musicals with no spoken text. One could argue that this puts them in the category of opera, but the industry regards them as musicals, and they are performed in theatres, not opera houses. An interesting case is Blitzstein's The Cradle Will Rock, which was billed as an opera when it premiered in the 30s but is now regarded as part of the musical theatre canon. Sondheim musicals tend to be not only "sung-through" but also "through-composed," with little melodic repetition and a lot of what opera people would call recitative. But they are still musicals. In fact, Sondheim is credited with initiating the shift from "musical comedy" to "musical theatre" and demonstrating the possibilities of the medium as a serious art form. The last couple of decades have seen an increasing number of "plays with music," which are dramas with a smattering of songs that don't conform to many of the conventions of musicals. But I digress.
Back to typography.)